first lessons learned from adopting mbse in early phases
TRANSCRIPT
1ESA UNCLASSIFIED – For ESA Official Use Only
First lessons learned from adopting MBSE in early
phases of complex satellite systems
Belen Gonzalez
29/09/2021
GNSS Evolutions and Strategy Division (NAV-PFS)
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Content
1. ELCANO overview
2. MBSE process for ELCANO Phase 0
3. Automatic Document Generation
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ELCANO overview (I)
PNT services provided by GNSS in MEO have become essential for many different commercial,
industrial, scientific and safety-critical applications.
GNSS in MEO (GPS, Galileo, ...) represents the backbone of PNT today. However, its service
provision is subject to:
- Limitations in coverage (multipath errors, outages in urban canyons, limited reach indoor).
- Other vulnerabilities (natural or man-made interference, spoofing).
A constellation in LEO may offer:
- Faster dynamics - Small/low- cost satellites
- Lower signal path loss - Global coverage
- Lower latency - Measurement diversity
- Frequency diversity
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o High Costs
o Long development times
- Traditional Satellite Navigation systems:
o Many stakeholders
o Interplay of many different disciplines/expertise
o Risk adverse programs
ELCANO system complexity
New Space approach: Lower costs & Fast-dynamics developments
- Scale down size, power and cost of payload while maintaining quality
of service
- Interoperable with existing systems
- Increased autonomy of a potential constellation with hundreds of satellites
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MBSE methodology used
Methodology
Language Tool
The fact that tool, language and methodology isincorporated in a single MBSE software programfacilitated our final choice of ARCADIA as the mostsuitable methodology.
derived from
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Architecture Levels - Arcadia
Operational Analysis
Logical Architecture
Physical Architecture
What the users of the system need to accomplish
What the system has to accomplish for the users
How the system will work to fulfil the expectations
How the system will be developed an built
Needs Understanding
Solution Architectural Design
System Analysis
ELCANO Phase 0
E-10 series
Specification/ Problem Space (black box)
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MBSE process. Operational Analysis
Mission Document
Operational Analysis
Operational Analysis
Identify stakeholders
To System Analysis
Identify Use Case
Model Operational Scenarios
Model Operational Processes
Challenges
• Many stakeholders involve
• Some mission concepts
difficult to model in detail
Solutions
• Focus on the user segment.
• Institutions to be added in a
later stage of the project.
• Build a strong model skeleton
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MBSE process. System Analysis
Mission Document
Operational Analysis
System Analysis
Identify Capabilities
for each Mission
Identify common
Capabilities
Check coherence
Need to go back to OA?
Solutions
• Diagrams better than requirements at this stage
To Document Generation
Operational Analysis
Challenges
• Mission capabilities definition
• Requirements management?
• Interfaces definition
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System Architecture in broadcast PNT from LEO
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Document Generation with M2Doc
What is M2Doc?
- An open-source add-on by Obeo that is used directly in Capella.
- M2Doc takes Word templates written in a language built on top of AQL as inputs to generate documents
automatically directly from the model.
- It enables flexible and custom document generation.
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Document Generation with M2Doc
Why do we needed M2Doc?
For complex systems: thousands of documents need to be created and maintained throughout the system life
cycle.
Their production, and maintenance require significant effort from all parties.
Manually (Copy/Paste info from the model) With M2Doc
Long process every time you need to update the
document
Time investment is made once (when the
template is written)
Prone to error Validation every time it generates a document
Difficult to verify consistency and completeness
of the document.
A change in the model is reflected in the
document
Every one in the SE team can do it You need someone in the SE team that can
code templates
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Document Generation process
Achievements
• Master the M2Doc tool
• Create process to automate
documentation generation.
Operational Analysis
M2DocStart new template
Know metamodel and code
Deal with compilation
errors
Solutions
• Training• Time investment• Forum consultation
Word Documents
Challenges
• Start from zero -> Little
documentation available
• Learn to navigate model
• Dealing with coding errors
Model in Capella
Master AQL
Achievements
• Coded templates for large documents
(~200 pages)
• Coded more simple templates to
check progress of the model: its
completeness and coherence.
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Document Generation Example
Generic document to control the status of the Model
This type document allows to do a quick check of the status of the model: completeness, justification and coherence.
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Conclusions
• M2Doc is a very powerful tool. It was proved very useful too generate large and very complete
documents from the model. Together with the HTML export of the model provides a full vision of the
model.
• Considerable time investment to learn to master it. However, the coded templates can be used as a
skeleton to develop more complex templates and validate the model as it evolves.
• The model coherence is essential to be able to navigate every part of the element to: extract
children, parents, exchanges, description, status…
From my experience, I would recommend to use M2Doc for complex systems which have to undergo major reviews/milestones.
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Q&A
Thank you for your attention. Any question?